The wetlands are important for wildlife, including some scarce breeding birds such as pied avocets, western marsh harriers, Eurasian bitterns and bearded reedlings.

Ducks and geese winter along this coast in considerable numbers, and several nature reserves provide suitable conditions for water voles, natterjack toads and several scarce plants and invertebrates.

The SSSI is economically important to the area because of the tourists it attracts for birdwatching and other outdoor activities, although sensitive wildlife sites are managed to avoid damage from the large numbers of visitors.

The Environment Agency considers that managed retreat is likely to be the long-term solution, and is working with the Norfolk Wildlife Trust to create new reserves inland to compensate for the loss of scarce habitats at the coast.

The SSSI is a long, narrow strip of coast that starts at the eastern boundary of The Wash between Old Hunstanton and Holme-next-the-Sea, and runs east for about 43 km (27 mi) to Kelling.

[1] The SSSI has a wide variety of habitats, with bare mud, sand and shingle characterising the intertidal zone along the whole of the coast, although higher areas may have algae or eelgrass that are grazed by ducks and geese in winter.

The salt marshes which form on sheltered coasts, in the lee of islands, or behind spits are described in the SSSI notification document as "among the best in Europe" due to their exceptionally diverse flora.

[3] A large Iron Age fort at Holkham enclosed 2.5 ha (6.1 acres) at the end of a sandy spit in what was then salt marsh, and remained in use until the defeat of the Iceni in 47 AD.

Blakeney gained its market charter in 1222, and the three ports, along with Salthouse, were jointly required to provide three ships for Edward II in 1322,[18] having previously contributed to his father's navy in 1301.

[3] By the early 15th century, Blakeney was one of the few ports permitted to trade in horses, gold and silver, through "merchants sworn by oath to the king", which contributed to the town's growing wealth.

Following the German naval attack on Great Yarmouth in November 1914, defences such as trenches, concrete pillboxes and gun batteries were constructed along much of the Norfolk coast.

[3] Between 1942 and 1945, the marsh was used by the Royal Tank Regiment;[21] an armoured fighting vehicle gunnery range was established and banks were constructed for firing practice, with targets set at 900 m (980 yd) intervals.

Some of the still extant islands were built to hold "pop-up" targets, operated by cables from winches in a building whose foundations now lie below a bird hide.

Bombing practice was supervised from a control tower, which was demolished in 1962, leaving only a concrete structure opposite the end of Titchwell's west bank.

[23] The SS Vina, an 1894 cargo steamer, was anchored offshore in 1944 for use as an RAF target, but a gale dragged her to the sands off Titchwell, where the wreck can still be seen at low tide.

[3] Royal Artillery military fortifications were established at Cley beach, including two 6-inch (15.24 cm) guns, five buildings, two pillboxes, a minefield,[3] and concrete anti-tank blocks.

[27] The first step towards the protection of this coast by a national conservation body was the purchase of Blakeney Point from the Calthorpe family by banker Charles Rothschild in 1912.

[28] In 1926, another early protected area was created when Norfolk birdwatcher Dr Sydney Long bought the land which makes up the Cley Marshes reserve for the sum of £5,100, to be held "in perpetuity as a bird breeding sanctuary".

[41][42] In spring and early summer, migrant birds including the little gull, black tern, Temminck's stint and garganey may pass through on their way to breed elsewhere.

In the autumn, birds arrive from the north; some, such as whimbrels, curlew sandpipers and little stints, just pausing for a few days to refuel before continuing south, others staying for the winter.

Scrubby sea-blite and matted sea lavender are characteristic plants of the drier upper salt marsh, although they are uncommon in the UK away from this coast.

It was made arable during World War II, but the water levels have been raised to make the fields attractive to breeding and wintering birds.

[39] Blakeney Point can also be reached by boats from Morston quay, either to see the seal colonies or to avoid the long walk up the shingle spit from Cley Beach.

[73] A 2005 survey at six North Norfolk coastal sites (Snettisham, Titchwell, Holkham, Morston Quay, Blakeney and Cley) found that 39 per cent of visitors gave birdwatching as the main purpose of their visit.

Wildlife may be disturbed, a frequent difficulty for species that breed in exposed areas such as ringed plovers, little terns and common seals, but also wintering geese.

[78] Damage is reduced by measures such as wardening breeding colonies, using fences, boardwalks and signs to control access, and appropriate positioning of car parks.

[81] Unlike the rapidly eroding soft cliffs further east,[82] the coast of the SSSI has shown a less consistent pattern, with a net accretion of beach material between 1880 and 1950.

[86] The landward movement of the shingle means that the channel of the River Glaven becomes blocked increasingly often, leading to flooding of the reserve and Cley village.

[89] The Environment Agency considered several remedial options to protect these vulnerable areas,[88] and a new route for the river to the south of its original line was completed in 2007 at a cost of about £1.5 million.

To compensate for the inevitable loss of the important reedbeds at Cley, the Environment Agency and the Norfolk Wildlife Trust have been working since 2010 to make a new wetland near Hilgay.